1. Field of the Invention
The invention relates to a low capacity nuclear reactor. More particularly, the invention relates to an underground reactor in the cavity of a cylindrical pressure vessel with a pile of spherical fuel elements through which cooling gas flows top to bottom aided by a blower. The reactor has a removable steel core vessel with a graphite reflector comprising bottom, side, and roof reflectors surrounding the pile. The side reflectors exhibit channels to contain a plurality of absorber rods.
2. Description of the Related Art
A nuclear reactor of the type shown in West German DE-OS No. 30 16 402 is a high temperature reactor of modular configuration. A metal vessel, containing a fuel element pile located in a cavity of a concrete vessel closed off by a cover may be lifted out from the concrete vessel together with a metal base plate and the bottom, side and roof reflectors. The removal may be effected only following shutdown of the reactor and discharge of the spherical fuel elements and removal of the control rods and opening of the cover. At least one line connected to the base plate leads downward to remove the heated cooling gas which flows through the pile from bottom to top. The hot gas line leads to a second cavity containing a heat consumer such as a steam generator arranged parallel to a first cavity in the concrete vessel. DE-OS No. 30 16 402 alternatively proposes to extend the cavity containing the nuclear reactor and to arrange the heat consumer under the metal vessel rather than utilize a second cavity.
The state of the art also includes the nuclear reactor installation described in DE-OS No. 33 35 451, a high temperature reactor with spherical fuel elements. In this installation all of the components of the primary loop, such as the control and shutdown devices, are arranged within a steel reactor pressure vessel so that they may be installed or removed from above. Economical subterranean construction is thus possible. At least one discharge tube under the high temperature reactor is provided for removal of fuel elements. The tube leads laterally out of the reactor pressure vessel.